(**************************************************************************)
(*                                                                        *)
(*                                 OCaml                                  *)
(*                                                                        *)
(*             Xavier Leroy, projet Cristal, INRIA Rocquencourt           *)
(*                                                                        *)
(*   Copyright 1996 Institut National de Recherche en Informatique et     *)
(*     en Automatique.                                                    *)
(*                                                                        *)
(*   All rights reserved.  This file is distributed under the terms of    *)
(*   the GNU Lesser General Public License version 2.1, with the          *)
(*   special exception on linking described in the file LICENSE.          *)
(*                                                                        *)
(**************************************************************************)

(* Environment handling *)

open Types

module PathMap : Map.S with type key = Path.t
                        and type 'a t = 'a Map.Make(Path).t

type summary =
    Env_empty
  | Env_value of summary * Ident.t * value_description
  | Env_type of summary * Ident.t * type_declaration
  | Env_extension of summary * Ident.t * extension_constructor
  | Env_module of summary * Ident.t * module_declaration
  | Env_modtype of summary * Ident.t * modtype_declaration
  | Env_class of summary * Ident.t * class_declaration
  | Env_cltype of summary * Ident.t * class_type_declaration
  | Env_open of summary * Path.t
  | Env_functor_arg of summary * Ident.t
  | Env_constraints of summary * type_declaration PathMap.t
  | Env_copy_types of summary * string list

type t

val empty: t
val initial_safe_string: t

val diff: t -> t -> Ident.t list
val copy_local: from:t -> t -> t

type type_descriptions =
    constructor_description list * label_description list

(* For short-paths *)
type iter_cont
val iter_types:
    (Path.t -> Path.t * (type_declaration * type_descriptions) -> unit) ->
    t -> iter_cont
val run_iter_cont: iter_cont list -> (Path.t * iter_cont) list
val same_types: t -> t -> bool
val used_persistent: unit -> Concr.t
val find_shadowed_types: Path.t -> t -> Path.t list
val without_cmis: ('a -> 'b) -> 'a -> 'b
        (* [without_cmis f arg] applies [f] to [arg], but does not
           allow opening cmis during its execution *)

(* Lookup by paths *)

val find_value: Path.t -> t -> value_description
val find_type: Path.t -> t -> type_declaration
val find_type_descrs: Path.t -> t -> type_descriptions
val find_module: Path.t -> t -> module_declaration
val find_modtype: Path.t -> t -> modtype_declaration
val find_class: Path.t -> t -> class_declaration
val find_cltype: Path.t -> t -> class_type_declaration

val find_type_expansion:
    Path.t -> t -> type_expr list * type_expr * int option
val find_type_expansion_opt:
    Path.t -> t -> type_expr list * type_expr * int option
(* Find the manifest type information associated to a type for the sake
   of the compiler's type-based optimisations. *)
val find_modtype_expansion: Path.t -> t -> module_type
val add_functor_arg: Ident.t -> t -> t
val is_functor_arg: Path.t -> t -> bool
val normalize_path: Location.t option -> t -> Path.t -> Path.t
(* Normalize the path to a concrete value or module.
   If the option is None, allow returning dangling paths.
   Otherwise raise a Missing_module error, and may add forgotten
   head as required global. *)
val normalize_path_prefix: Location.t option -> t -> Path.t -> Path.t
(* Only normalize the prefix part of the path *)
val reset_required_globals: unit -> unit
val get_required_globals: unit -> Ident.t list
val add_required_global: Ident.t -> unit

val has_local_constraints: t -> bool
val add_gadt_instance_level: int -> t -> t
val gadt_instance_level: t -> type_expr -> int option
val add_gadt_instances: t -> int -> type_expr list -> unit
val add_gadt_instance_chain: t -> int -> type_expr -> unit

(* Lookup by long identifiers *)

(* ?loc is used to report 'deprecated module' warnings *)

val lookup_value:
  ?loc:Location.t -> Longident.t -> t -> Path.t * value_description
val lookup_constructor:
  ?loc:Location.t -> Longident.t -> t -> constructor_description
val lookup_all_constructors:
  ?loc:Location.t ->
  Longident.t -> t -> (constructor_description * (unit -> unit)) list
val lookup_label:
  ?loc:Location.t -> Longident.t -> t -> label_description
val lookup_all_labels:
  ?loc:Location.t ->
  Longident.t -> t -> (label_description * (unit -> unit)) list
val lookup_type:
  ?loc:Location.t -> Longident.t -> t -> Path.t
  (* Since 4.04, this function no longer returns [type_description].
     To obtain it, you should either call [Env.find_type], or replace
     it by [Typetexp.find_type] *)
val lookup_module:
  load:bool -> ?loc:Location.t -> Longident.t -> t -> Path.t
val lookup_modtype:
  ?loc:Location.t -> Longident.t -> t -> Path.t * modtype_declaration
val lookup_class:
  ?loc:Location.t -> Longident.t -> t -> Path.t * class_declaration
val lookup_cltype:
  ?loc:Location.t -> Longident.t -> t -> Path.t * class_type_declaration

val copy_types: string list -> t -> t
  (* Used only in Typecore.duplicate_ident_types. *)

exception Recmodule
  (* Raise by lookup_module when the identifier refers
     to one of the modules of a recursive definition
     during the computation of its approximation (see #5965). *)

(* Insertion by identifier *)

val add_value:
    ?check:(string -> Warnings.t) -> Ident.t -> value_description -> t -> t
val add_type: check:bool -> Ident.t -> type_declaration -> t -> t
val add_extension: check:bool -> Ident.t -> extension_constructor -> t -> t
val add_module: ?arg:bool -> Ident.t -> module_type -> t -> t
val add_module_declaration: ?arg:bool -> check:bool -> Ident.t ->
  module_declaration -> t -> t
val add_modtype: Ident.t -> modtype_declaration -> t -> t
val add_class: Ident.t -> class_declaration -> t -> t
val add_cltype: Ident.t -> class_type_declaration -> t -> t
val add_local_constraint: Path.t -> type_declaration -> int -> t -> t
val add_local_type: Path.t -> type_declaration -> t -> t

(* Insertion of all fields of a signature. *)

val add_item: signature_item -> t -> t
val add_signature: signature -> t -> t

(* Insertion of all fields of a signature, relative to the given path.
   Used to implement open. Returns None if the path refers to a functor,
   not a structure. *)
val open_signature:
    ?used_slot:bool ref ->
    ?loc:Location.t -> ?toplevel:bool -> Asttypes.override_flag -> Path.t ->
      t -> t option

val open_pers_signature: string -> t -> t

(* Insertion by name *)

val enter_value:
    ?check:(string -> Warnings.t) ->
    string -> value_description -> t -> Ident.t * t
val enter_type: string -> type_declaration -> t -> Ident.t * t
val enter_extension: string -> extension_constructor -> t -> Ident.t * t
val enter_module: ?arg:bool -> string -> module_type -> t -> Ident.t * t
val enter_module_declaration:
    ?arg:bool -> Ident.t -> module_declaration -> t -> t
val enter_modtype: string -> modtype_declaration -> t -> Ident.t * t
val enter_class: string -> class_declaration -> t -> Ident.t * t
val enter_cltype: string -> class_type_declaration -> t -> Ident.t * t

(* Initialize the cache of in-core module interfaces. *)
val reset_cache: unit -> unit

(* To be called before each toplevel phrase. *)
val reset_cache_toplevel: unit -> unit

(* Remember the name of the current compilation unit. *)
val set_unit_name: string -> unit
val get_unit_name: unit -> string

(* Read, save a signature to/from a file *)

val read_signature: string -> string -> signature
        (* Arguments: module name, file name. Results: signature. *)
val save_signature:
  ?check_exists:unit ->
  deprecated:string option -> signature -> string -> string -> Cmi_format.cmi_infos
        (* Arguments: signature, module name, file name. *)
val save_signature_with_imports:
  ?check_exists:unit -> 
  deprecated:string option ->
  signature -> string -> string -> (string * Digest.t option) list
  -> Cmi_format.cmi_infos
        (* Arguments: signature, module name, file name,
           imported units with their CRCs. *)

(* Return the CRC of the interface of the given compilation unit *)

val crc_of_unit: string -> Digest.t

(* Return the set of compilation units imported, with their CRC *)

val imports: unit -> (string * Digest.t option) list

(* [is_imported_opaque md] returns true if [md] is an opaque imported module  *)
val is_imported_opaque: string -> bool

(* Direct access to the table of imported compilation units with their CRC *)

val crc_units: Consistbl.t
val add_import: string -> unit

(* Summaries -- compact representation of an environment, to be
   exported in debugging information. *)

val summary: t -> summary

(* Return an equivalent environment where all fields have been reset,
   except the summary. The initial environment can be rebuilt from the
   summary, using Envaux.env_of_only_summary. *)

val keep_only_summary : t -> t
val env_of_only_summary : (summary -> Subst.t -> t) -> t -> t

(* Error report *)

type error =
  | Illegal_renaming of string * string * string
  | Inconsistent_import of string * string * string
  | Need_recursive_types of string * string
  | Depend_on_unsafe_string_unit of string * string
  | Missing_module of Location.t * Path.t * Path.t
  | Illegal_value_name of Location.t * string

exception Error of error

open Format

val report_error: formatter -> error -> unit


val mark_value_used: t -> string -> value_description -> unit
val mark_module_used: t -> string -> Location.t -> unit
val mark_type_used: t -> string -> type_declaration -> unit

type constructor_usage = Positive | Pattern | Privatize
val mark_constructor_used:
    constructor_usage -> t -> string -> type_declaration -> string -> unit
val mark_constructor:
    constructor_usage -> t -> string -> constructor_description -> unit
val mark_extension_used:
    constructor_usage -> t -> extension_constructor -> string -> unit

val in_signature: bool -> t -> t
val implicit_coercion: t -> t

val is_in_signature: t -> bool

val set_value_used_callback:
    string -> value_description -> (unit -> unit) -> unit
val set_type_used_callback:
    string -> type_declaration -> ((unit -> unit) -> unit) -> unit

(* Forward declaration to break mutual recursion with Includemod. *)
val check_modtype_inclusion:
      (loc:Location.t -> t -> module_type -> Path.t -> module_type -> unit) ref
(* Forward declaration to break mutual recursion with Typecore. *)
val add_delayed_check_forward: ((unit -> unit) -> unit) ref
(* Forward declaration to break mutual recursion with Mtype. *)
val strengthen:
    (aliasable:bool -> t -> module_type -> Path.t -> module_type) ref
(* Forward declaration to break mutual recursion with Ctype. *)
val same_constr: (t -> type_expr -> type_expr -> bool) ref

(** Folding over all identifiers (for analysis purpose) *)

val fold_values:
  (string -> Path.t -> value_description -> 'a -> 'a) ->
  Longident.t option -> t -> 'a -> 'a
val fold_types:
  (string -> Path.t -> type_declaration * type_descriptions -> 'a -> 'a) ->
  Longident.t option -> t -> 'a -> 'a
val fold_constructors:
  (constructor_description -> 'a -> 'a) ->
  Longident.t option -> t -> 'a -> 'a
val fold_labels:
  (label_description -> 'a -> 'a) ->
  Longident.t option -> t -> 'a -> 'a

(** Persistent structures are only traversed if they are already loaded. *)
val fold_modules:
  (string -> Path.t -> module_declaration -> 'a -> 'a) ->
  Longident.t option -> t -> 'a -> 'a

val fold_modtypes:
  (string -> Path.t -> modtype_declaration -> 'a -> 'a) ->
  Longident.t option -> t -> 'a -> 'a
val fold_classs:
  (string -> Path.t -> class_declaration -> 'a -> 'a) ->
  Longident.t option -> t -> 'a -> 'a
val fold_cltypes:
  (string -> Path.t -> class_type_declaration -> 'a -> 'a) ->
  Longident.t option -> t -> 'a -> 'a

(** Utilities *)
val scrape_alias: t -> module_type -> module_type
val check_value_name: string -> Location.t -> unit

module Persistent_signature : sig
  type t =
    { filename : string; (** Name of the file containing the signature. *)
      cmi : Cmi_format.cmi_infos }

  (** Function used to load a persistent signature. The default is to look for
      the .cmi file in the load path. This function can be overridden to load
      it from memory, for instance to build a self-contained toplevel. *)
  val load : (unit_name:string -> t option) ref
end
